This invention relates to communication networks, and more particularly to a method and apparatus for managing a subtended communication network.
A digital subscriber line (xDSL) multiplexer provides communication service between subscribers and a communication network. When the xDSL multiplexer can no longer handle additional subscribers, a second xDSL multiplexer may couple to the first xDSL multiplexer such that the second xDSL multiplexer communicates with the communication network through the first xDSL multiplexer. The two xDSL multiplexers are now in a subtending relationship. Coupling the second xDSL multiplexer to the first xDSL multiplexer increases the number of subscribers serviced without having to establish another connection to the communication network.
When two, or more, xDSL multiplexers couple together in a subtending relationship, it becomes important to provision the address space used by each xDSL multiplexer to prevent conflicting use of the same addresses. To effectively provision the address spaces, however, it is necessary to first know the subtending relationship between the xDSL multiplexers.
The present invention substantially reduces or eliminates at least some of the disadvantages and problems associated with managing digital subscriber line (xDSL) multiplexers in subtending relationships. The present invention provides a communication network that allows a management module, and other management modules, to discover the subtending relationship between xDSL multiplexers in a subtending relationship by synchronizing with information stored in the xDSL multiplexers.
In one embodiment of the present invention, a subtended communication network includes a first node servicing a plurality of first subscribers and having a subtend module and a corresponding first identifier. The first node is operable to store a second identifier corresponding to a second node coupled to the subtend module. The communication network also includes a second node servicing a plurality of second subscribers and having a network interface module and corresponding second identifier. The second node is operable to store the first identifier corresponding to the first node coupled to the network interface module. The communication network further includes a management module coupled to the first node and the second node. The management module is operable to determine a subtending relationship between the first node and the second node by retrieving the first identifier from the second node and the second identifier from the first node.
In another embodiment, a node coupled to a subtended node in a subtended communication network includes a plurality of subscriber ports coupled to a plurality of subscribers receiving communication service from the node. The node also includes a subtend module coupled to a subtended node and operable to store an identifier for the subtended node. The node further includes a network interface module coupled to a data network. In addition, the node includes a switch operable to receive first subscriber data from the subscriber ports and second subscriber data from the subtend module and to communicate the first subscriber data and the second subscriber data to the network interface module for communication over the data network.
The present invention has several important technical features and advantages. First, because each node stores identifiers for the nodes adjacent to it, meaning the nodes coupled to it as either subtended or subtending nodes, a management module may determine the subtending relationship between all of the nodes in the network upon the discovery of only one of the nodes. This avoids a manual configuration of the subtending relationship in the management module. Determining the subtending relationship between all of the nodes allows efficient management of the subtended communication network. Also because each node stores identifiers for adjacent nodes, the management module can use the identifiers stored at a node to establish or replace identifiers stored for the node at the management module. This form of synchronization may be necessary when the management module first discovers a node or when the identifiers already stored for the node at the management module become corrupted. Further, because the management module stores identifiers for adjacent nodes, the management module may replace the identifiers stored at a node with the identifiers stored at the management module for the node. This form of synchronization may be necessary if the identifiers stored at the node become corrupted or upon replacement of one of the nodes. In addition, because of the storage of the identifiers for adjacent nodes at each node, if a second management module with no knowledge of the subtending relationship discovers any one of the nodes, the second management module can determine the subtending relationship between the nodes without assistance from the first management module. Thus, the second management module does not have to undergo a manual configuration. Other technical advantages will be readily apparent to one skilled in the art from the following figures, description, and claims.